Profiled resilient band for securing filier bag

ABSTRACT

A filtering apparatus has a bag or sleeve connected to a profiled resilient band (10, 20). The band is operative to sealing engage an aperture (13, 16) in a further body (16, 27). The profiled band (10, 20) has a one piece construction.

BACKGROUND OF THE INVENTION

The present invention relates to a filtering apparatus.

With the filtering apparatus of the kind which comprise at least onefilter bag or filter sleeve it is common practice to provide a sealingring around the periphery of the bag or sleeve.

GB 1603110 describes a filtering apparatus comprising a bag or sleevehaving a sealing arrangement comprising a ring of felt having a radiallyoutwardly directed flange. A spring steel or rubber ring is providedbetween the filter material and the felt ring. In use, the felt flangeis received in an appropriately profiled rim of an aperture in apartition wall through which the bag is disposed. In practice, theflange is built up by appropriate application of strips of felt.Alternatively plastics, rubber rings, ropes and so forth may be used tobuild up the flange. Much time and effort is taken up in making theseproducts and considerable skill is required.

SUMMARY OF THE INVENTION

The present invention has been made from a consideration of thisproblem.

According to the present invention there is provided a filteringapparatus comprising a filter bag or sleeve, a profiled resilient bandconnected to a part of the filter bag or sleeve, the profiled band beingoperative to sealingly engage, or being operative to cause the filterbag or sleeve to sealingly engage, the periphery of an aperture in afurther body, wherein the profiled band has a one piece construction andwherein holes and/or slots are provided in the band.

Since the profiled band has a one piece construction, this eliminatesthe effort and skill involved in making such profiled bands from anumber of separate parts. Accordingly the bands are less expensive tomanufacture.

The resilience may be provided by using a resilient material, such asspring stainless steel or hard rubber. However, it is desirable that thebands are easily compressible by hand while being sufficiently resilientto retain their original shape when the compressive force has beenremoved. This is achieved by providing holes, slots or the like in theband, particularly in the projections forming the profiled regions ofthe band. In some embodiments of the invention it is desirable toprovide open ended holes, slots or the like at one or both edges of theband.

The top of the filter bag or sleeve may be secured to the band bysewing, adhesive or welding. The band imposes a profile on the top ofthe filter fabric.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be more readily understoodspecific embodiments thereof will now be described by way of exampleonly with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of one filter band in accordance with theinvention; and

FIG. 2 is a side elevation of a second filter band in accordance withthe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 a filtration apparatus comprises a filter sleeve(not shown) secured to an endless sealing band 10. The band 10 is madefrom spring stainless steel, typically in the order of 0.38 mm thick.Two projections 11,12 extend radially outwardly from the band 10 so asto define a channel 13 therebetween. A number of slots 14a, 14b areprovided in the band in the region of the projections so as to ensurethat the projections are readily resiliently deformable. In someinstances separate slots 14a are provided in the two projections and inother locations an elongated single slot 14b is provided which spansboth projections. The band 10 is secured directly to the filter sleeveby sewing or welding.

In use the band is received in an aperture 15 defined by a cell plate16. One of the projections is compressed by hand and inserted into theaperture 15 at which time the projection springs outwardly and theboundary of the aperture 15 is securely captured in the channel 13defined between the projections 11 and 12. The channel 13 sealinglyengages the boundary of the aperture 15 such that a dust tight seal isprovided.

Referring to FIG. 2 a second spring stainless steel band 20 comprisesprojections 21,22 defining a channel 23 therebetween. A plurality ofopen ended slots 24 are provided at one end of the band 20. The freeends of the flanges 25 defining the slots are directly inwardly. Theband is secured directly to the top of the filter sleeve by sewing orwelding.

In use the band is inserted in direction "A" into an aperture 26 in afilter cell plate 27. As the ends of the flanges 25 are directlyinwardly the flanges automatically move inwardly as the band is insertedinto the aperture 26. Once in position the flanges 25 spring outwardlyand the cell plate is securely captured in the channel 23 so as toprovide a dust tight seal.

The bands described above are considerably easier and cheaper tomanufacture than known sealing bands for filter sleeves, but remainsimple to use and effective in operation.

It is to be understood that the above described embodiments have beendescribed by way of illustration only. Many modifications and variationsare possible.

I claim:
 1. A filtering apparatus comprising a filter bag or sleeve, aprofiled resilient band connected to a part of the filter bag or sleeve,the profiled band being operative to sealingly engage, or beingoperative to cause the filter bag or sleeve to sealingly engage, theperiphery of an aperture in a filter body, the profiled band having aone piece construction and a profiled region comprising one or moreprojections defining a channel, and holes or apertures provided in saidprofiled region of the band.
 2. A filtering apparatus as claimed inclaim 1, wherein the band comprises a resilient material.
 3. A filteringapparatus as claimed in claim 1, wherein the band comprises springstainless steel.
 4. A filtering apparatus as claimed in claim 1, whereinthe band comprises rubber.
 5. A filtering apparatus as claimed in claim1, wherein the holes or apertures are provided in at least one edge ofthe band.
 6. A resilient band for sealingly engaging a filter bag orsleeve in an aperture of a filtering apparatus which comprises aprofiled region having at least one projection defining a channel, and,openings provided in said profiled region to permit said projection tocompress upon engagement with the periphery of the aperture and assistin seating of said periphery in said channel.
 7. The resilient band ofclaim 6, wherein the band is a one piece member.
 8. The resilient bandof claim 6, wherein the band comprises a spring stainless steel.
 9. Theresilient band of claim 6, wherein the band comprises rubber.
 10. Theresilient band of claim 6, wherein the openings comprise slots or holes.